Posted on 09/15/2012 7:55:47 PM PDT by smokingfrog
The engine installed on every Boeing 787 built in South Carolina so far has a problem.
The first sign something was wrong came on a Saturday afternoon in July when the second locally made Dreamliner experienced a pre-flight engine failure as it accelerated down the runway at Charleston International Airport.
A month and a half later, the extent of the defect has become clearer — and bigger.
The North Charleston incident was not isolated, as had been the original hope. Instead, two other General Electric-made GEnx engines have been found to suffer from a similar defect in the drive shaft.
And the concern is that the problem could be even more widespread, inherent to the make-up of the engine itself.
That news came Friday afternoon as the National Transportation Safety Board, which has been investigating the July 28 incident, issued a pair of urgent safety recommendations regarding the fan midshafts of GEnx engines.
The NTSB called on the Federal Aviation Administration to require ultrasound inspections of all GEnx-powered 787s and 747s not already inspected before any further flight.
The NTSB also recommended that the FAA require repetitive inspections of the fan midshafts of all GEnx engines “at a sufficiently short interval that would permit multiple inspections and the detection of a crack before it could reach critical length and the FMS fractures.”
That’s what happened in Charleston in July and on Tuesday as a Boeing 747-8F cargo jet was preparing to take off from Shanghai.
(Excerpt) Read more at aikenstandard.com ...
And who is the Idiot that put those Red Letters right on top of the Compressor Blades? Those sharp corners will tear them up, especially the “q” that's sticking down into the mechanism.
Are those guys Color Blind or something? I can clearly see the problem and I used to be a Corporate Manager, not a Jet Engine Mechanic.
My brother says Rolls Royce engines are better than GE and P&W.
I’m sure he’s not prejudiced, even though he works for Rolls Royce.
Hat tip.
Now that’s funny.
I regret I didn’t think of it first.
It sure was.
So to avoid overspeeding the Turbine, they intentially allow the LPT Rotors to crash into the LPT stators, because that is safer than the alternative (a grenade).
That would mean there is no reverse thrust loaded Bearing aft of this part that breaks... hmmmmmmmm....
I wonder if normal takeoff run ups are considered "extreme stress events".
GE is going to have to walk a fine line if they want to make a part that doesn't break, yet breaks when they want it to and not have the airline inspect it every 10 flights to see if its breaking yet. They are asking a lot out of IHI.
Presumably the engine control shuts the fuel down immediately upon sensing the turbine overspeed. However, I wonder if it continues to windmill during flight; I suppose this could be a problem.
I wear my hat proudly.
A similar incident occured in Japan recently.
Junk engines.
If there is instantly no load on the LPT, it would only take a second for the LPT to overspeed enough to throw all the blades... Don’t know if shutting off the fuel would work fast enough.
GE doesn’t either, which is apparently why they are using their LPT stator vanes as a Brake.
The LPT is making about 80,000 Shaft HP to spin the fan. If it no longer has to spin anything, that 80,000 HP is going to go somewhere else, real quick.
http://www.geaviation.com/engines/commercial/genx/firstflight.html
Victorville.
We took a tour of the facility and the test 747.
Don’t worry buddy, I stole it too!
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